In an LTE network, a common mobility management policy of an evolved Node B (eNB) is to make a switching judgement on a User Equipment (UE) with reference to a signal difference between a serving cell and a neighbour of the serving cell. Here, the serving cell refers to a cell currently accessed by the UE.
Usually, a coverage area where signals are overlapped with those of other LTE cells exists at the edge of an LTE cell. When a UE moves from the centre of a serving cell to the edge of the serving cell, a signal of the serving cell will be decreased gradually, and a signal of the neighbour of the serving cell will be increased gradually. When the signals of the serving cell and the neighbouring cell satisfy preset threshold values, the eNB can switch the UE to the neighbouring cell, and the neighbour of the original serving cell, as a new serving cell of the UE, serves the UE.
Generally, before the eNB makes a judgement to switch the serving cell, the signal situations of the serving cell of the UE and the neighbour thereof may be acquired through a connected-state measurement mechanism, and the eNB can control and process measurement behaviours of a connected UE, such as additions, deletions or modifications of measurement configurations of the UE. Specifically, the eNB configures the UE through a Radio Resource Control protocol (RRC) Connection Reconfiguration message of a Uu interface to measure the serving cell or the neighbour and report the measurement; the UE measures the serving cell or the neighbour according to the measurement configurations of the eNB, and after satisfying conditions for trigger the measurement configurations, the UE reports a measurement result to the eNB through a Measurement Report of the Uu interface; and the eNB makes a policy decision, to switch the UE to other cells for instance, according to a measurement result reported by the UE, wherein the Uu interface is an air interface between the UE and an Evolved UMTS Terrestrial Radio Access Network (E-UTRAN).
In the LTE network, in order to indicate relative signal changes of the serving cell and the neighbouring cell, the eNB may configure the UE with a measurement event matching the UE, such as an A3 measurement event: Mn+Ofn+Ocn−Hys>Ms+Ofs+Ocs+Oft, where Mn is a signal measurement result of the neighbouring cell, Ofn is a frequency offset of a frequent point of the neighbouring cell, Ocn is an individual offset of the neighbouring cell, Hys is a hysteresis parameter, Ms is a signal measurement result of the serving cell, Ofs is a frequency offset of the serving cell, Ocs is an individual offset of the serving cell, and Off is an event threshold. The UE detects the measurement results of the serving cell and the neighbouring cell to evaluate whether the measurement results satisfy the conditions of the event, and if so, measurement reporting is triggered. During the evaluation of the measurement event, the UE uses a cell (a listed cell) indicated in a neighbouring-cell list of a measured carrier frequency object and a cell (a detected cell) which is not indicated in the neighbouring-cell list of measured carrier frequency object to evaluate the event. As long as the listed cell or the detected cell satisfies the conditions for triggering the measurement event, the UE sends a measurement result to the eNB through a Measurement Report, the Measurement Report containing a signal measurement result of the serving cell, a physical cell identifier of a neighbouring cell and a signal measurement result of the neighbouring cell.
For measurement event with a handover purpose, the eNB cannot accurately locate a target cell of handover in accordance with the physical cell identifier of the neighbouring cell in a measurement report only, and it is necessary for the eNB to determine the target cell of the handover by mapping the physical cell identifier of the neighbouring cell into an Evolved Cell Global Identifier (ECGI) containing a mobile country code, a mobile network code and a cell identifier. If the UE sends all detected cells to the eNB through a Measurement Report, then when the eNB determines to switch to the target cell, mapping the physical cell identifier of the neighbouring cell into an ECGI may fail. For example, a physical cell mapping rule is not determined, that is a neighbouring relation is not configured, which may cause failure in measurement processing.
In the traditional art, on one hand, it is complicated, effort-consuming and fallible to configure an LTE system with a mapping rule, namely an inter-cell neighbouring relation, and the situation that neighbouring cells are missed to be configuration may frequently occur; and on the other hand, a network environment of an actual commercial scene is complicated, it is probable for a cell to adjust the signal coverage, and the difficulty in configuration of a neighbouring relation is improved. Thus, failure in measurement for handover is common in a network, which causes a great amount of invalid measurement signalling interaction through air interfaces in the network.
Currently, the problem can be solved using a technology for configuration of a automatic neighbouring relation. However, it is necessary for the UE and the eNB to support a technology related to the automatic neighbouring relation, and the configuration technology of the current neighbouring relation is not forcibly required in standard and is optional. Thus, it cannot be guaranteed that all UEs and all eNBs support the automatic neighbouring relation. Even if the UE supports the technology related to the automatic neighbour, in view of a process that the UE performs relevant measurement according to the automatic neighbour relation technology, other service functions of a terminal will be influenced inevitably. Consequently, network operators may start an automatic neighbouring relation function in a specific period and a specific area according to their own requirements.